Add missing PR number
Add missing PR number

Add missing PR number in the changelog entry.

mqliang/etcd,etcd-io/etcd,mqliang/etcd,rnaveiras/etcd,gyuho/etcd,mkumatag/etcd,gyuho/etcd,rnaveiras/etcd,ajityagaty/etcd,coreos/etcd,mkumatag/etcd,ajityagaty/etcd,coreos/etcd,etcd-io/etcd,mqliang/etcd,etcd-io/etcd,ajityagaty/etcd,mkumatag/etcd,rnaveiras/etcd